electronics in sophisticated sensors developed
by biotechnologist Isao Karube of the Univer
sity of Tokyo. Dr. Karube's enzymes measure
the alcohol content of wine and beer and the
freshness of sushi. Placed in hospital toilets,
the sensors monitor the health of patients, as
indicated by minerals deposited with urine.
* Enhanced oil recovery: Microbes play a
growing role in wringing oil from faltering
wells. The opportunity is enormous. In U. S.
oil fields an estimated 50 billion barrels await
improved recovery techniques.
"Hundreds of wells are stimulated yearly
using microbes," said Thomas E. Burchfield
of the National Institute for Petroleum and
Energy Research in Bartlesville, Oklahoma.
"For example, bacteria remove clogging par
affins. A company can inject microbes down a
well or simply stimulate the bugs already there
with nutrients-most often molasses."
* Coal desulfurization: The acid rain that
threatens lakes and forests in North America
traces in large measure to sulfur from coal
combustion. Bacteria show promise of remov
ing much of that sulfur before the coal is
burned. Research is under way at the Institute
of Gas Technology in Chicago and DOE's
Idaho National Engineering Laboratory.
* Nitrogen fixation: French chemist Louis
Pasteur recognized in the 1800s that soil
microbes are essential to life; they are the
primary force for fracturing tough molecules
of atmospheric nitrogen and making it avail
able for plants. These bacteria, often of the
genus Rhizobium, live in the roots of plants,
principally legumes.
Agriculturists have sought to extend this
process to other crops and thus reduce our
dependence on chemical fertilizers that pollute
the environment. It has proved a challenge.
NationalGeographic, August 1993